1. Field of the Invention
The present invention relates to a manufacturing method for a semiconductor device having circuit elements that are resin-sealed on a surface of a semiconductor substrate.
2. Description of the Related Art
In a conventional way of resin-sealing semiconductor elements formed on the front surface of a semiconductor substrate (e.g., silicon substrate) for a purpose of protection, the peripheral portion of the semiconductor substrate is secured with a special die, for example, and the semiconductor substrate is then covered with resin. Because of this, resin is provided only in the inner area on the surface where the semiconductor elements are formed, and resin is not provided on the peripheral area of the semiconductor substrate. Consequently, a step difference for the thickness of the resin is generated between the inner area and the peripheral area on the substrate surface. Normally the thickness of the substrate is adjusted by polishing the rear face of the semiconductor substrate after resin-sealing. Impact due to grinding or the like makes the semiconductor substrate unstable due to the step difference formed in the substrate peripheral portion, and this creates chips and cracks in the semiconductor substrate. In order to solve this problem, Japanese Patent Application Kokai (Laid-Open) No. 2005-19435, for example, discloses a wafer polishing method for removing the peripheral portion of the semiconductor substrate by cutting or polishing before polishing the rear face of the semiconductor substrate.
If the peripheral portion of the semiconductor substrate is removed, as disclosed in Japanese Patent Application Kokai No. 2005-19435, the resin existing in the boundary between the inner area and the peripheral portion on the surface is peeled or removed upon cutting or polishing. As a result, the instability that is generated during polishing the rear face of the semiconductor substrate cannot be prevented, and chips and cracks are generated in the semiconductor substrate. Load is also applied to the semiconductor substrate itself by cutting or polishing when the peripheral portion is removed, and chips and cracks are generated in the semiconductor substrate due to this vibration and shock.